Note: Descriptions are shown in the official language in which they were submitted.
WO93/18126 C A 2 1 1 7 6 4 1 PcT/us93/ol792
SUDS CONTROLLING COMPOSITIONS
Technical Field
The present invention relates to suds controlling
compositions and stable liquid detergent compositions
containing them.
Backqround
It has become common practice in the detergent industry to
include in detergent compositions materials which are intended
to control the amount of foam produced during a washing cycle
in a washing machine.
Silicone antifoam agents in finely dispersed form have been
found to be particularly effective species, and efforts have
been directed towards increasing the stability of such agents
upon prolonged storage in liquid detergent compositions
containing them.
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However, it has found to be difficult to create and maintain
the finely dispersed form of the silicone antifoam agents in
liquid detergent compositions, especially in a high ionic
strength medium.
In U.S. 4,798,671, it has been proposed to make a premix of
dispersing agents and suds controlling agents to obtain storage
benefits.
Surprisingly, it has now been found that improved storage
stability of suds controlling agents in liquid detergent
compositions can be achieved by adding to said agents a
polymer-based latex. According to the present invention, a
suds controlling composition is provided which has improved
stability upon storage when incorporated into liquid
detergents.
According to another embodiment of the present invention, a
stable liquid detergent composition comprising said suds
controlling composition is provided.
According to still another embodiment of the present
invention, a process is provided to obtain stable liquid
detergent compositions comprising the suds controlling
composition of the present invention.
Summary of the Invention
The present invention provides suds controlling composition
for inclusion in a detergent composition in liquid form,
comprising a silicone antifoam agent, a carrier material, a
dispersant and a polymer-based latex.
The present invention also provides liquid detergent
compositions comprising said suds controlling composition,
surface-active agents and optionally other detergent
ingredients.
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Detailed DescriPtion of the Invention
The sllicone antifoam aqent
In industrial practice, the term "silicone" has become a
generic term which encompasses a variety of relatively high-
molecular-weight polymers containing siloxane units and
hydrocarbyl groups of various types. Generally, the silicone
antifoam agent can be described as siloxanes having the general
structure :
~~(~SI~~)n~~
I
R
wherein n is from 20 to 2.000, and where each R independently
can be an alkyl or an aryl radical. Examples of such
substituents are methyl, ethyl, propyl, isobutyl, and phenyl.
Preferred polydlorganosiloxanes are polydimethylsiloxanes
having trimethylsilyl endblocking units and having a viscosity
at 25~C of from 5 x 10-5 m2/s to 0.1 m2/s i.e. a value of n in
the range 40 to 1500. These are preferred because of their
ready availability and their relatively low cost.
A preferred type of silicone antifoam agent useful in the
co~.positions herein comprises a mixture of an alkylated
siloxane of the type hereinabove disclosed and solid silica.
The solid silica can be a fumed silica, a precipitated silica
or a silica made by the gelformation technique. The silica
particles can be rendered hyrophobic by treating them with
diaklylsilane groups and/or trialkylsilane groups either bonded
directly onto the silica or by means of silicone resin.
A preferred antifoam agent comprises a hydrophobic silanated,
most preferably trimethylsilanated silica having a particle
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size in the range from lO nanometer to 20 nanometer and a
specific surface area above 50 m2/g.
Silicone antifoam agents employed in the suds controlling
composition suitable for to the present invention have an
amount of silica in the range of 1 to 30%, more preferably from
1 to 20% by weight of the total weight of the silicone antifoam
resulting in silicone antifoams having an average viscosity in
the range from 2 x 10~4m2/s to 1m2/s..
Preferred silicone antifoams may have a viscosity in the range
of from S x 10~3m2/s to 0.1 m2/s.
Particularly suitable are silicone antifoams with a viscosity
of 2 x 10~2m2/s or 4.5 x 10~2m2/s.
Examples of suitable silicone antifoam agents which are
commercially available are QCF2-3329, QCF2-3421, Q2-3302
manufactured by Dow Corning.
The silicone antifoam agent is present in the suds
controlling composition at levels of from 2% to 20% by weight,
preferably 5% to 10~ by weight of the suds controlling
composition.
The carrier material
The suds controlling composition of the present invention
comprise the silicone anti-foam agent in the form of a
dispersion in a water-soluble or water-dispersable organic
carrier.
Suitable organic carriers are nonionic surfactants.
Preferably, the nonionic surfactants are ethoxylated
surfactants. In general, ethoxylated nonionic surfactants
suitable herein have an average ethyleneoxy content in the
range from 35% to 70% and especially from 50% to 62.5% by
weight of the surfactant.
Examples of suitable nonionic surfactants include the
condensation products of primary or secondary aliphatic
alcohols having from 8 to 24 carbon atoms, in either straight
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chain or branched chain configuration, with from 2 to 18 moles
of alkylene oxide per mole of alcohol. Preferably, the
aliphatic alcohol comprises between 9 and 15 carbon atoms and
is ethoxylated with between 2 and 9, desirably between 3 and 8
moles of ethylene oxide per mole of aliphatic alcohol.
Most preferred are alkoxylated nonionic surfactants having an
average HLB in the range from 9.5 to 13.5, especially 10 to
12.5. Highly suitable nonionic surfactants of this type are
ethoxylated primary C9-15 alcohols having an average degree of
ethoxylation from 2 to 9, more preferably from 3 to 8.
The carrier is present in the suds controlling composition at
levels from 30% to 95% by weight, preferably 80% to 90% by
weight of the total suds controlling composition.
DisPersant
The suds controlling composition of the present invention
comprises a dispersing agent.
The dispersing agent disperses or helps disperse the silicone
antifoam agent uniformly so that stable, preferably isotropic,
detergent formulas can be prepared. The d-spersing agent is
premixed with the silicone antifoam agent prior to
incorporation into the liquid detergent com~osition.
Suitable dispersing agents include materials such as ethylene
oxide adducts of linear or arylphenols having from 8 to 20
car~,n atoms per molecule, such as lauryl polyoxethylene glycol
ether, stearyl polyoxyethylene, glycol ether, cetyl
polyoxyethylene glycol ether, and nonylphenol polyGxyethylene
glycol ether, and also ethylene oxide adducts of linear or
branched monocarboxylic acids and having HL8s of greater than
about 13.5, preferably greater than about 14. Preferably, such
addition products have short hydrophylic chains containing 12
or preferably less carbon atoms and from about 8 to about 15
et~ylene oxide units per molecule. Other examples of preferred
dispersants are polyoxyethylene glycol sorbitan esters of
polyoxyethylene glycol sorbital esters having HLB values of 14
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or more, such as polyoxyethylene glycol sorbitan hexaoleate or
polyoxyethylene sorbitol hexaoleate. Additional examples of
preferred dispersants are fatty acid mono-,di-, and/or
polyglycerides and sodium or calcium stearoyl lactate,
diglycerol stearate, and sorbitan monostearate. The suds
controlling composition of the present invention can contain a
single type of dispersant or mixtures of at least two different
types of dispersants.
Other useful dispersants are commercial oxyethylated
polyhydric alcohols or their derivatives or similar compounds
having an active hydrogen atom, as well as fatty acid esters of
glycerol or sorbitol.
Anionic emulsifiers, such as sodium dodecylbenzene-sulphonate
or sodium laurylsulphate, can also be used, but preferably with
a solvent.
Preferred is an emulsifier mixture of oxyethylated fatty
alcohol and oxyethylated triglyceride having an HLB value
preferably in the range from about 14 to 16.
The preferred solvent for dimethylpolysiloxane is tetrameric
or pentameric cyclomethicone. Particularly preferred
dispersants for use herein are cyclomethicone and C9-C11 linear
chain alcohols ethoxylated with from about 7 to about 10 moles
of ethylene oxide per mole of alcohol especially when the
unreacted alcohol and monoethoxylated alcohol are removed and
mixtures thereof.
The most preferred dispersants are mixtures of silicone glycol
copolymers and cyclomethicone compounds. Examples of said
mixtures which are commercially available are DC3225C
manufactured by Dow Corning.
The amount of dispersant is from 1% to 20%, preferably from 1%
to 5% by weight of the suds controlling composition.
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The PolYmer-based latex
The silicone antifoam compounds, as described hereinabove,
must be present in the liquid detergent compositions in finely
dispersed form in order to be effective. However, the
particles of the antifoam agent present in the liquid detergent
composition tend to coagulate upon storage, thereby becoming
less efficient antifoam agents.
According to the present invention, it has been found that
improved stability of the silicone antifoam ' _unds can be
achieved by adding small amounts of polymer-based latex to the
silicone antifoam compounds. The concept of "stability" as
used herein is in the context of maintaining the silicone
antifoam agent in finely dispersed form.
The addition of low levels of polymer-based latex reduces the
coalescence of the silicone antifoam particles so that stable
detergent formulas can be prepared. The polymer-based latex
consists of finely divided particles of polymer dispersed in a
surfactant matrix. The polymer-based latices are mainly
prepared by polymerizing low moleculair weight monomers in a
free radical emulsion polymerisation system.
Suitable monomers that can be used to make the polymer-based
latex are styrene, C1-C4 alkyl acrylate, ethylene, butadiene,
vinylchloride, vinylidene chloride or mixtures thereof.
Preferred polymer-based latices for use in the present
invention are polystyrene-baSed latices comprising homo-and
copolymers of polystyrene. Examples of such polystyrene-based
latex are commercially known as Lytron 631, comprising 40~ of
polystyrene raw material dispersed in nonionic surfactant
solution.
Other suitable polymer-based latex are butadiene-styrene,
butadiene-acrylonitrille, butadiene-styrene-acrylonitrile and
chloroprene based latices .
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The polymer present in the polymer based-latex typically have a
particle size from 50 to 300 nanometer, preferably from 50 to
200 nanometer. By "size" herein is meant average particle
diameter for substantially spherical particles, or the size of
the largest diameter or dimension for nonspherical particles
Preferably, the polymer present in the polymer -based latex has
a small particle size distribution.
Preferred particle sizes distributions can be chosen such that
80% of all the particles have a particle size varying between
80% and 120% of the average particle size . Most preferred
particle size distributions have 90% of all particles varying
between 80% and 120% of the average particle size.
The polymer-based latex 15 present in the suds controlling
composition preferable from 1% to 40%, preferably from 1% to
15% by weight of the suds controlling composition.
The level of the polymer-based latex, present in the liquid
detergent composition is preferable from 0.01% to 0.12%, more
preferable from 0.01% to 0.08~ by weight of the total detergent
composition.
In terms of processing, the compounds of the suds controlling
composition are premixed before incorporation into the liquid
detergent composition. The suds controlling composition of the
present invention is made by mixing the silicone antifoam
agent,the carrier material, the dispersant and the polyTer -
based L~x in a high shear mixer. The high shear mix can be
prepared using any conventional high shear mixing equipment.
The suds controlling composition of the present invention
can also be incorporated in detergent additive products.
Such additive products are intended to supplement or boost the
performance of conventional detergent compositions and may
contain any of the components of such compositions.
The liquid detergent compositions comprising the suds
- controlling composition of the present invention is made by
mixing the suds controlling composition together with detergent
ingredients. The liquid detergent compositions comprising the
suds controlling composition can be provided having various
ratios and proportions of the detergent additives.
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The amount of suds controlling composition in the liquid
detergent composition can be varied, dependinq upon the suds
profile desired by the formulation. The level of the suds
controlling composition is preferable present from 0.8% to 3.0%
by weight of the total detergent composition.
Deterqent inqredients
In another embodiment of the present invention, a liquid
detergent composition is provided comprising the suds
controlling composition of the present invention mixed with
detergent ingredients. Detergent ingredients include
surfactants, builders and optional detergent additives.
A wide range of surfactants can be used in the detergent
composition of the present invention.
A typical listing of anionic, nonionic, ampholytic and
zwitterionic classes, and species of these surfactants, is
given in US Patent 3,664,961 issued to Norris on May 23, 1972.
Mixtures of anionic surfactants are particularly suitable
herein, especially mixtures of sulphonate and sulphate
surfactants in a weight ratio of from 5:1 to 1:2, preferably
from 3:1 to 2:3, more preferably from 3:1 to 1:1. Preferred
sulphonates include alkyl benzene sulphonates having frcm 9 to
15, especially 11 to 13 carbon atoms in the alkyl radical, and
alpha-s~1phnnAted methyl fatty acid esters in which the fatty
acid is derived from a C12-Clg fatty source preferably from a
C16-C18 fatty source. In each instance the cation is an alkali
metal, preferably sodium. Preferred sulphate surfactants are
alkyl sulphates having from 12 to 18 carbon atoms in the alkyl
radical, optionally in admixture with ethoxy sulphates having
from 10 to 20, preferably 10 to 16 carbon atoms in the alkyl
radical and an average degree of ethoxylation of 1 to 6.
Examples of preferred alkyl sulphates herein are tallow alkyl
sulphate, coconut alkyl sulphate, and C14_1s alkyl sulphates.
The cation in each instance is again an alkali metal cation,
preferably sodium.
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One class of nonionic surfactants useful in the present
invention are condensates of ethylene oxide with a hydrophobic
moiety to provide a surfactant having an average hydrophilic-
lipophilic balance (HLB) in the range from 8 to 17, preferably
from 9.S to 13.5, more preferably from 10 to 12.5. The
hydrophobic (lipophilic) moiety may be aliphatic or aromatic in
nature and the length of the polyoxyethylene group which is
condensed with any particular hydrophobic group can be readily
adjusted to yield a water-soluble compound having the desired
degree of balance between hydrophilic and hydrophobic elements.
Especially preferred nonionic surfactants of this type are
the Cg-Cl5 primary alcohol ethoxylates containing 3-8 moles of
ethylene oxide per mole of alcohol, particularly the C14-C15
primary alcohols containing 6-8 moles of ethylene oxide per
mole of alcohol and the C12-C14 primary alcohols containing 3-s
moles of ethylene oxide per mole of alcohol.
Another class of nonionic surfactants comprises alkyl
polyglucoside compounds of general formula
RO (CnH2nO)tzx
wherein Z is a moiety derived from glucose; R is a saturated
hydrophobic alkyl group that contains from 12 to 18 carbon
atoms; t is from 0 to 10 and n is 2 or 3; x is from 1.3 to 4,
the , -c including less than 10% unreacted fatty alcohol
and less than 50% short chain alkyl polyglucosides. Compounds
of this type and their use in detergent are disclosed in EP-B 0
070 077, 0 075 996 and 0 094 118.
Also suitable as nonionic surfactants are poly hydroxy fatty
acid amide surfactants of the formula
R2 - C - ~i - Z
Il I
O Rl
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wherein Rl is H, or R1 is Cl_4 hydrocarbyl, 2-hydroxy ethyl, 2-
hydroxy propyl or a mixture thereof, R2 is Cs_~ hydrocarbyl,
and Z is a polyhydroxyhydrocarbyl having a linear hydrocarbyl
chain with at least 3 hydroxyls directly connected to the
chain, or an alkoxylated derivative thereof. Preferably, Rl is
methyl, R2 is a straight Cll_l5 alkyl or alkenyl chain such as
coconut alkyl or mixtures thereof, and Z is derived from a
reducing sugar such as glucose, fructose, maltose, lactose, in
a reductive amination reaction.
The compositions according to the present invention may
further comprise a builder system. Any conventional builder
system is suitable for use herein including aluminosilicate
materials, silicates, polycarboxylates and fatty acids,
materials such as ethylenediamine tetraacetate, metal ion
sequestrants such as aminopolyphosphonates, particularly
ethylenediamine tetramethylene phosphonic acid and diethylene
triamine pentamethylenephosphonic acid. Though less preferred
for obvious environmental reasons, phosphate builders can also
be used herein.
Suitable builders can be an inorganic ion exchange material,
commonly an inorganic hydrated aluminosilicate material, more
particularly a hydrated synthetic zeolite such as hydrated
zeolite A, X, B or HS.
Another suitable inorganic builder material is layered
silicate, e.g. SKS-6 (Hoechst). SKS-6 is a crystalline layered
silicate consisting of sodium silicate (Na2Si2o5).
Suitable polycarboxylates builders for use herein include
citric acid, preferably in the form of a water-soluble salt,
derivatives of succinic acid of the formula R-CH(COOH)cH2(cooH)
wherein R is C10-20 alkyl or alkenyl, preferably C12-16, or
wherein R can be substituted with hydroxyl, sulfo sulfoxyl or
sulfone substituents. Specific examples include lauryl
succinate , myristyl succinate, palmityl succinate2-
dodecenylsuccinate, 2-tetradecenyl succinate. Succinate
builders are preferably used in the form of their water-soluble
salts, including sodium, potassium, ammonium and
alkanolammonium salts.
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Other suitable polycarboxylates are oxodisuccinates and
mixtures of tartrate monosUccinlc and tartrate disuccinic acid
such as described in US 4,663,071.
Especially suitable fatty acid builders for use herein are
saturated or unsaturated C10-18 fatty acids, as well as the
corresponding soaps. Preferred saturated species have from 12
to 16 carbon atoms in the alkyl chain. The preferred
unsaturated fatty acid is oleic acid. Another preferred
builder system for liquid compositions is based on dodecenyl
succinic acid.
Other suitable water-soluble organic salts are the homo- or co-
polymeric acids or their salts, in which the polycarboxylic
acid comprises at least two carboxyl radicals separated from
each other by not more than two carbon atoms.
Polymers of this type are disclosed in GB-A-1,596,756.
Examples of such salts are polyacrylates of MW 2000-So00 and
their copolymers with maleic anhydride, such copolymers having
a molecular weight of from 20,000 to 70,000, especially about
40,000.
Detergency builder salts are normally included in amounts of
from 10% to 80~ by weight of the composition preferably from
20~ to 70% and most usually from 30% to 60~ by weight.
Other components used in detergent compositions may be
employed, such enzymes and stabilizers or activators therefore,
soil-suspending agents soil-release agents, optical
brighteners, abrasives, bactericides, tarnish inhibitors,
coloring agents, and perfumes.
The liquid compositions according to the present invention
can also be in "compact form", in such case, the liquid
detergent compositions according to the present invention will
contain a lower amount of water, compared to conventional
liquid detergents.
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Test ~rocedure
To assess the stabilizing effect of the added polymer-based
latex, the stability of the suds controlling compositionS
incorporated in liquid detergent compositions are compared in
the absence and presence of the polymer-based latex. More in
particular, the stability of polydimethyl siloxane/fumed silica
was determined in the absence and in the presence of
polystyrene latex.(Lytron 631)
The stability of the samples were measured after several
periods of storage at 21~C. The stability was determined by
visual inspection of the samples :
Liquid detergent compositions according to the present
invention, containing the finely dispersed form of the silicone
antifoam agent have a translucent appearance.
Coalescence of the particles of the silicone antifoam agent
causes flocculation of said particles, resulting in a change of
visual appearance of the bulk solution from translucent to
transparent.
The following examples are meant to exemplify compositions of
the present inventions, but are not necessarily meant to limit
the scope of the invention.
A liquid detergent composition according to the present
invention is prepared, having the following c~~positions :
W093/18126 C A 2 i 1 7 6 4 1
by weight of the total detergent composition
I II
Linear alkylbenzene sulfonate lO 15
Alkyl sulphate 4
Fatty alcohol (Cl2-Cl5) ethoxylate 9 14
Fatty acid S l0
oleic acid 4
Citric acid S 9
KOH
NaOH 5 4
Monoethanolamine 9
Propanediol l.S 9
Ethanol 5.
Minors up to lOO
The above compositions I and II were each supplemented by the
suds controlling compositions A and B (Table I). The
components of the suds controlling composition were premixed
before being added to the liquid detergent compositions. The
stability of the samples IA, I3, IIA, IIB were determined after
several weeks of storage at 21~C
TABLE I
Ingredien~s Percentage by weight of the total
detergent composition
A B
Polydirnethyl silo~aDe/fumed siGca 0 . 2 0 .2
Dispcrsant ~ ~ ~ 7 ~ ~ ~ 7
Nonionic 1. 8 1. 8
Polvstyrenc latcJ~ ~ O . 08
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Results :
IA IB
Fresh -homogeneously -homogeneously
dispersed dispersed
-translucent -translucent
lwk -homogeneously -homogeneously
dispersed dispersed
-translucent -translucent
3wk -flocculation -h~ 35neo~cly
dispersed
-translucent
6wk -increased h. -3eneously
flocculation dispersed
-transparent -translucent
IIA IIB
Fresh -homogeneously -homogeneously
dispersed dispersed
-translucent
lwk -h~ 7enp~l~cly -homogeneously
dispersed dispersed
translucent
3wk -flocculation -homogeneously
dispersed
-translucent
6wk -increased -homogeneously
flocculation dispersed
transparent translucent
In AhscDnc~ of the polymer-based latex the finely dispersed
sllicone antifoam agent starts to agglomerate and flocculate
upon storage, resulting in a transparent liquid.
In the presence of polymer-based latex, the finely dispersed
silicone antifoam agent remains homogeneously dispersed in the
liquid, resulting in a translucent liquid.
As can be seen from the results, the addition of low levels of
polystyrene based latex greatly improves the stability of the
finely dispersed silicone antifoam agent in the liquid
detergent composition even upon long periods of storage.
